The effects of a single-sex educational setting on girls' computing experience and attitudes were investigated. Questionnaire data were collected from a sample of 231 high school girls (aged approximately 15 years) from three single-sex and two co-educational schools in Victoria, Australia. Girls from single-sex settings were found to have more experience with computers, and more positive attitudes toward computers than girls from co-educational settings. However, once the effects of experience with computers were partialed out, there was no effect of educational setting on computing attitudes. Diversity of computing experience was the strongest predictor of high school girls' attitudes toward computers. The findings indicate the importance of designing computing curricula for girls which emphasize a broad range of computing activities in preference to focusing on skill development in a single area.